I have a column chart that is empty when the user first selects the webscreen. On the same screen, there is a record list containing the data of an aggregate. Now I want to have a checkbox per each record list item. When the checkbox is ticked, I want the column chart to show the values of the corresponding data series (I already have a function that will take the record list item's or entity's id and return the right data series in form of a data point list.). If the checkbox is unticked, the corresponding data series should be removed from the column chart.

However I can't work out which variable to use for the checkbox (add boolean attribute to entity? add boolean column to aggregate? etc...) and how to dynamically refresh the column chart. I have tried the mentioned ways but it didn't work.

For the checkbox you just need to add an extra Boolean column to the aggregate that starts with true this way all the checkbox will be ticked in the beginning. To change the chart on the checkbox add an onchange action where you change the variable with the correct data points and Ajax refresh the chart.